Block-signaling system.



Patented July 20, 190%.

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Patented July 20, 1909.

APPLICATION FILED JAN. 29, 1909.

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DANIEL J. MCCARTHY, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR {TO THE UNION SWITCH dz SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

BLOCK-SIGNALING SYSTEM.

Patented ma 20. 1 one Application filed January 29, 1909. Serial No. 474,937.

To all who-m it may concern:

Be it known that I, DANIEL J. MCCARTHY, of lNilkinsburg, Allegheny county, Pennsylvania have invented av new and useful Improvement in BlocloSignaling Systems, of which the followin is a full, clear, and exactdescription, re erence being had to the accompanying drawings, formingpart of this specification, in which- Figures 1, 2 and 3 are diagrammaticviews illustrating different embodiments of my invention.

My invention has relation to block-signaling apparatus, more particularly to a signaling system employing home and distant or three-position signals. In this class of block signals where the distant signal arm or-the clear position of the three'position signal is controlled by the movement ofthe home signal for the block in advance, it has been customary to effect this control, when alternating current is used in the track circuits and the transformer is placed at the enter ing end of the block, by a reversal of the polarity of the track circuit through polechanging devices operated by the home signal in advance. When, however, the transformers, whl h supply signaling currents to the respective blocks, are placed at the central portions of the blocks, this method can not be employed.

The present invention is designed to pro vide a simple and eiiicient method of controlling distant signals or the clear position of three-position signals when the transformer is placed at the central portion of the block;

A further object is to provide a signaling system of this character in which the circuits are sil'np ified and a saving is efiected in the amount of line wire and relays required for the o aeration.

The nature 0 my invention will be best understood from the accompanying drawings, in which I have shown threeembodiments thereof and which will now be described, it being premised, however, that various changes may be made in the details of construction and arrangement of the various parts by thos skilled in the art, withoutdeparting from the spirit and scope of my invention as defined in the appended claims.

Referring to Fig. 1, the numerals 2 and 3 designate the track rails which are divided into the block sections it, B and O by the insulated joints 4. 5 designates the home signal guardmg the entrance to the block [5,

and 6 is the corres 'ionding distant signal for is omitted in the drawings for the purpose of simplification. 8 designates a tl1reeposition relay having one of its elements, in this case, the rotor or armature element, connected across the track rails 2 and 3 at a point near the entrance of the block B. 9 is a transformer having its primary connected across the signal supply mains 10 and 11, and its secondary connected across the track rails 2 and at the central portion of the block B. 12 is a relay having one element, in this case, its rotor or armature element, connected across the track rails 2 and -3 at a point near the leavin r end of the block B. 13 is an impedance coil which is connected across the signal mains 10 and 11. Connected to the central portion of the impedance coil 13 is a conductor 14 which includes a coil or windingl5, forming the other element oi the relay 8, the conductor'extending to the other end of the block-and passing through contacts 16, controlled by the movable arm 17 of the relay 12'. The distant end of the conductor 14 is connected to the movable arm 18 ofa twoposition switch, which is connected by a suitable connection with the signal 7. The two stationary contacts 19; and 20 of the two-position switch 18 are respectively connected to opposite sides of the signal maips 10 and 11, as shown, a coil 21, also connected across said mains, forming the other elen'icnt of the relay 12. The relay 8 is provided with the front contacts 22, 23,

and 24, for enga ement with the movable arm 25 of the re ay 8, and with the back contacts 26 and 27, which are also en aged by said arm in its other position. hese front and back contacts are connected with theactuating mechanism of the signal blades 5 and 6. In the position of the arm 25, shown in full lines in Fig. l, the circuits of the actuating mechanisms of both blades are closed and both blades are in their clear positions In the intermediate dotted position of the arm 25, the circuits of the actuating mechanisms of both these blades are ea es opened and both blades are in their anger positions, this dotted position being the deenergized position of the relay. In the third position of the arm 25, the circuit of the ,5 actuating mechanism for the home signal arm is closed and that signal is cleared, while the circuit for the actuating mechanism of distant signal (S is opened and the signal .6 remains at danger. in Assuming that at any instant current is flowing from the line wire to the line wire 11, it will be seen that current will be flowin the conductor 14-. from the two-position or reversing switch 18, toward the re- 15 lav 8, and through the coil or winding 15 c that relay to the middle point of the imiojedance coil 13, and thence through onehalf of that coil to the line wire or signal main 13.. i This holds the relay 3 in the .position shown in full lines in Fig. 1, with both ls-ignalsfi and 6 cleared. When, however, the signel'bladc mov es to danger position, the arm 13 is shifted from the contact 20 to the contact. 19, thereby. shifting the connection ,ofth'edistant end at the conductor 14: from f' the liiteovire 10 to the line wire 11. )urrent 1 llow's through the other half of the imd'pedahce coil and through the conductor let the reverse. (li'ection. This reverses the 3;. position of the relay 8 and moves its arm 25 1 into engagementwith the back contacts 28 id 27. Y lit willhseen that as soon as the train tore the left hand end of the block section the relay 3 will co short-circuited and ,d to its intermediate position, t1 ereby the. circuit of the actna ting mechanisms of both signal blades 5 and 6, and setboth thesehlades at dan er. The relay 8 did remains short-circuited until the train has ypassed beyond the transformer 9, when the inlay 17, is, in turn short-circuited, thus l eyeing the circuit of the coil 15 open and holding the relay 8 in its middle or deenergized position. As soon as the train passes out of block B into the bloclr C, relay 1'? again closes and completes the circuit of the coil 1.5. As soon, however, as the train e'ntersthe bloclr section C, the signal blade 7 is moved to danger position, and thereby shifts theswitch 18, to reverse the direction of current flowing in the coil 15. This reverses the relay 8 to clear the home signal 5 and to hold the distant signal 6 at danger. When the home signal 7 clears, the current in coil 15 is again reversed and the distant signal-6 is cleared.

The system shown in Fig. 2 is the same in all respects as that shown in Fig. 1, except so that instead of employing home and distant 'signal'hlades, a single three-position blade 'rnployedat the entrance to each block. h hree positions of these blades are indieaten in dotted The other parts hein' Q?" the as Fig. are given the same and 36 may be of t erence characters as in that figure. It will be readily seen that the movements of the relays 8 are controlled in the same manner as in Fig. l, and-that these movements control the three positions of the blades 28.

In the arrangement shown in Fig. 3, 29 is a three-position relay which corresponds to the relay 8 of Figs. 1 and 2, and which controls the home and distant signal blades at the entrance to block B. In this figure, however, this relay has one winding 30, which is connected across the signal mains l0 and 1 1, and another winding b1, which is connected at one end to the middle point of the winding 30 and at its other end to a conductor 32, which corresponds to the conductor 14 of Figs. 1 and 2. This conductor and also through the contacts 35 of a track relay 34, at the entrance end of the block B and also through the contacts 35 of a track relay 36, connected across the rails at the leaving end of the block B, the contacts 33,

being in series. The relay 29 is preferably of the split-phase induction motor type in which it is necessary that the current in one of the windings be out of phase with that in the other winding, this being accomplished by the connection of the winding 31 to the middle point of the winding 30, and the coils being so designed as to give the 90 necessary different phase relations. It will be apparentthat the reversal of current in either of the windings30 or 31 will cause a reversal in the direction of rotatic n of the armature 9 of the relay. The track relays 0 35 and 36 may be of any suitable character. in the drawings I have shown them each as having one element connected across the track rails and a second element supplied with current by secondaries of the transformers 37 and 38, these transformers being connected across the signal mains 10 and 11. The other parts of Fig. 3, which correspond to similar parts in Figs. 1 and 2, are given similar reference characters to those in Figs. l and 2. The operation of this is substantially the same as that of the system shown in Fig. 1, as the shifting of the switch arm 1.8 by the movement of the home signal 7 will reverse the current in the windings 30 and 31 of the relay 29, to thereby reverse the relay. The object of using the relay 29 is to keep the high voltage of the line of the signal mains 10 and 11 out of the windin of the track relay 34, when this voltage is high enough to be objectionable for use in the relay of the tyge shown. The relays 34 e vane type with'but one actuating element and that connected directly across the track rails. The signaling mains l0 and 11 may be supplied wit alter: mating current from any suitable source, not shown;

It will be noted that in both forms of my invention, I provide for the clearing of the i ceases distant signal by the use of a single conductor extending back from the signal in advance, thus greatly reducing the amount of Wire which is required, as Well as simplifying the system as a'whole.

I claim:

1. In a block signaling system, signaling means for indicating the condition of two successive blocks,

a three-position relay for controlling the si naling means, a source of supply for signa ing current connected to each block at the central portion thereof, a

single conductor connected tothe said source of supply at both ends of the block and having means for controlling the position of the relay, and means controlled by the. movement of the advance home signal for reversing the current in said conductor to thereby reverse the relay, substantially as described.

2. In a block signaling system, sectional track rails forming block sections, signaling means for indicatlng the condition of two adjacent sections, a three-position relay for controlling the signalin means located at the entrance end of the block, a track relay connected across the opposite end portionof the block section, said three-position relay having an ener izing element, the opposite terminals of said element being connected to signal mains at opposite ends of the block by a conductor controlled by the track relay, and means controlled by the advance home signal for reversing the direction of current through the energizing element, substantially as described. i

3. In. a bloclnsignaling system, a track divided into block sections, signal means for indicating the condition of two adjacent block sections, 'a three-position relay for controlling the signal 1neans, supply lines or mains for si middle portion of each block, an impedance coil connected across said mains, a conductor connected to the intermediate portion of the impedance coil and including a Winding constituting an energizing element for the relay,

naling current connected to the till tacts controlled by the track relay, and a reversing switch operated by the advance home signal and arranged to connect the dis taut end of said conductor with either one oi the signal mains, substantially as described.

l. In a block signaling system, a track rail divided into block sections, signaling current lines or mains havinga supply connection with each block section at the intermediate portion thereof, signal means for indicating thecimditiou of two adjacent blocks, a three position relay for controlling the signal means, a coil connected across the signal mains at one end of the block, a conductor leading from the intermediate portion of said coil to the opposite end of the block, a track relay at the opposite end of the block having contacts controlling said conductor, and a shifting switch controlled by the advance home signal for connecting said conductor to either one of the signal mains, said coil forming a means for controlling the action of the three-position relay, substantially as described.

5. In a block signal system, a tlareeposition relay for controlling the signals, current supplymains, a coil connected across said mains at one end portionof the block, and arranged to control the position of the relay, a conductor leading from the central portion of the coil to the opposite end of the block, and means controlledby the passage of a train out of the advance block for reversing the current in said conductor, substantially as described.

In testimony Whereor, l have hereunto set my hand.

DANIE L J. MCCARTHY. 

